The present invention relates to a window assembly for a motor vehicle including an automotive window and a sealing element for the window to be bonded to an edge portion of a window aperture, in which the sealing element features a mounting portion adapted to be bonded to the inside of the window, and in which the sealing element includes a sealing lip, projecting from the mounting portion, which can be brought in contact with an edge of the window aperture.
A prior art window assembly is known from German document DE 199 61 706 A1. The window assembly comprises a sheet and a sealing element which is secured to the inside of the sheet via a mounting portion. The sheet is bonded with an adhesive seam to an edge portion of a section of the vehicle body enclosing the fixed window. An elastic sealing lip projects from the mounting portion, and the mounting portion and the sealing lip are made of synthetic materials. However, below the mounting portion, an additional supporting element extruded from another synthetic material can be present. When the window assembly is installed in vehicle body section, the free end of the sealing lip rests on the edge portion of the vehicle body section.
German document DE 36 02 198 C1 describes a window assembly in which a seal encompassing the edge of an automotive window sheet serves to secure the window assembly in place until an adhesive seam is hardened.
European document EP 99 460 B1 discloses a window assembly including an automotive window sheet and a seal secured to the edge of the window sheet with a mounting portion and an elastic sealing lip projecting therefrom. The sealing lip is connected to the mounting portion via a flexible bridge, thereby enabling the sealing lip to be pried from a gap present between the edge of the window and the edge of the vehicle body section to allow, for example, the edge portion of the vehicle body to be repainted.
One object of the invention is to optimize a window assembly of the type described above.
The invention teaches that this object can be achieved by providing a window assembly in which, over its length, the sealing lip has at least a first layer and a second layer which are placed adjacent to each other and which are tightly bonded to one another, and in which the first layer forms an external surface layer and features a higher resistance to temperature than the second layer, which underlies the first layer. Further embodiments and features of the invention are also claimed.
Advantages achieved through the invention include permitting repainting of the edge portion of a vehicle body section followed by subsequent heat treatment for drying the applied coating to be performed without the external appearance of the external surface layer of the sealing lip being significantly compromised by temperatures normally used in the paint drying process. The properties of the second layer below the external surface layer can be adjusted to meet the desired sealing properties.
Through the presence of at least two layers, the resiliency of the sealing lip can be optimized, allowing it to rest securely on the edge of the vehicle body section. This property can be achieved by making the external surface layer of a harder material than the second layer since the harder synthetic material can provide sufficient resiliency.
In a preferred embodiment, the mounting portion of the sealing element is a bearing designed to rest on the edge portion of the window aperture, and the window assembly can be mounted on the edge portion of the vehicle body as a prefabricated assembly. In this option, the bearing also serves to create space between the automotive window sheet and the edge portion of the vehicle body to allow an adhesive seam to be placed therein.
The assembly, including an automotive window sheet and a sealing element, can be temporarily secured to the edge portion of the vehicle body by way of a self-adhesive strip on a bonding surface of the bearing that is to make contact with the edge portion of the window aperture. The self-adhesive strip, in this case, holds the window assembly in the desired position until the adhesive seam is sufficiently hardened and the window assembly is permanently fixed into position and secured to the edge portion of the vehicle body.
According to one embodiment, in which the bearing is bonded to an inside of the automotive window with a self-adhesive strip, the assembly can be manufactured in a simple and economical manner by combining an automotive window sheet with a sealing element.
In a particularly advantageous embodiment, the sealing lip has a notch on its contact surface facing an edge of the automotive window. If the sealing lip rests with elasticity against the edge portion of the vehicle body section, it can be stretched sufficiently far in the direction of the edge of the automotive window sheet that the edge lies in the notch, thereby making additional sealing and weather-stripping components unnecessary.
An embodiment of the invention is described in further detail below with reference to the illustrations.